Work gear-type clamping devices, such as those found in the below-listed U.S. patents are widely employed since they offer many advantages over spring-type and other fixed diameter devices. For example, such worm gear clamping arrangements are more convenient to use than the analogous spring type devices, do not require special tools for installation and removal, as do many types of spring-type clamping devices, and allow adjustment in accordance with the particular material and dimensions of the associated element to which a clamping force is to be applied. Worm gear clamping devices in the prior art do, however, suffer from a number of disadvantages which include the problems arising from the use thereof in corrosive environments due, primarily, to the fact that such prior art worm gear clamping devices are fabricated of metallic materials. Such corrosion makes removal of these worm gear clamping devices extremely difficult and may subject the devices to premature failure. Additionally, numerous components are usually required to manufacture the prior art clamping devices, rendering them either expensive to produce, and/or time consuming to assemble.
In order to overcome the shortcomings of prior art worm gear clamping devices, it has heretofore been proposed to manufacture such devices from a polymeric material, as is exemplified in some of the below listed patents; however, the prior known and used worm gear-type clamping devices that have been fabricated of from polymeric materials, such as plastic, have also been found to be objectionable from the standpoint that relatively small torque loads may be applied to the worm gears thereof, resulting in inherent limitation of the clamping force which can be applied by the devices.
The present invention provides a solution to the aforementioned problems of not only prior know spring-type clamping devices, but also metallic and plastic-type worm gear clamping devices in the prior art, whereby to provide a new and improved clamping arrangement which can be used in highly corrosive environments, and where relatively large clamping forces must be applied thereby. In particular, the present invention provides a new and improved clamping device which is fabricated entirely of a polymeric material, whereby to assure against attrition due to corrosion and the like. The particular worm gear employed in the clamping device of the present invention is operatively associated with an enclosure member or housing, both of which are designed such that relatively large torque loads may be applied to the worm gear without undesirable deflection or deformation of the worm gear occurring which, in the past, has been a significant limitation in prior known plastic or polymeric fabricated clamping devices.
It is accordingly a general object of the present invention to provide a new and improved hose-type clamping device.
It is a more particular object of the present invention to provide a new and improved clamping device of the above character which is fabricated entirely of a polymeric material.
It is yet a more particular object of the present invention to provide a new and improved clamping device which may have relatively large applications of torque applied to the worm gear thereof so as to be capable of exerting a proportionately large clamping load to an associated workpiece.
It is another object of the present invention to provide a new and improved clamping device, as above described, which incorporates a double enveloping worm gear form so as to provide a large degree of contact between the gear teeth and the associated threads on the clamping strap so as to overcome the disadvantages of prior known clamping devices wherein only line contact occurs between the worm gear teeth and the associated teeth of the clamping strap.
It is a further object of the present invention to provide a new amnd improved clamping device, as above described, which is intended to be assembled by sonic welding techniques, so as to minimize assembly time and expense.
It still a further object of the present invention to provide a new and improved clamping device of the above character wherein the housing or enclosure for the worm gear defines an interior cavity or chamber, the profile of which is of a complementary configuration with respect to the profile of the worm gear, so as to minimize to the extreme, the likelihood of any movement or deformation of the worm gear within the housing during the applications of large torque loads thereto.
It is still a further object of the present invention to provide a new and improved clamping device, as above described, wherein the housing is symmetrical in shape and thereby may be installed or assembled upon the associated clamping strap regardless of the end-to-end orientation of the housing with respect to the strap, thus minimizing assembly time.
Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawing.